VerifyStage: headers validation using preferified hashes.

src/downloader/downloader_impl.rs

@@ -2,8 +2,9 @@ use crate::downloader::{
     chain_config::{ChainConfig, ChainsConfig},
     headers::{
         fetch_receive_stage::FetchReceiveStage, fetch_request_stage::FetchRequestStage,
-        header_slices::HeaderSlices, refill_stage::RefillStage, retry_stage::RetryStage,
-        save_stage::SaveStage, verify_stage::VerifyStage,
+        header_slices::HeaderSlices, preverified_hashes_config::PreverifiedHashesConfig,
+        refill_stage::RefillStage, retry_stage::RetryStage, save_stage::SaveStage,
+        verify_stage::VerifyStage,
     },
     opts::Opts,
     sentry_client,
@@ -79,7 +80,10 @@ impl Downloader {
 
         let retry_stage = RetryStage::new(Arc::clone(&header_slices));
 
-        let verify_stage = VerifyStage::new(Arc::clone(&header_slices));
+        let verify_stage = VerifyStage::new(
+            Arc::clone(&header_slices),
+            PreverifiedHashesConfig::new(&self.opts.chain_name)?,
+        );
 
         let save_stage = SaveStage::new(Arc::clone(&header_slices));
 

src/downloader/headers/mod.rs

@@ -2,6 +2,7 @@ pub mod header_slices;
 
 pub mod fetch_receive_stage;
 pub mod fetch_request_stage;
+pub mod preverified_hashes_config;
 pub mod refill_stage;
 pub mod retry_stage;
 pub mod save_stage;
@@ -14,5 +15,6 @@ pub use ui_crossterm::HeaderSlicesView;
 
 #[cfg(not(feature = "crossterm"))]
 pub mod ui_tracing;
+
 #[cfg(not(feature = "crossterm"))]
 pub use ui_tracing::HeaderSlicesView;

src/downloader/headers/preverified_hashes_config.rs

@@ -0,0 +1,56 @@
+use serde::{de, Deserialize};
+use std::str::FromStr;
+
+/// The preverified hashes is a list of known precomputed hashes of every 192-th block in the chain:
+///
+/// hash(0), hash(192), hash(384), hash(576), ...
+///
+/// The preverified hashes are copied from:
+/// https://github.com/ledgerwatch/erigon/blob/devel/turbo/stages/headerdownload/preverified_hashes_mainnet.go
+/// https://github.com/ledgerwatch/erigon/blob/devel/turbo/stages/headerdownload/preverified_hashes_ropsten.go
+pub struct PreverifiedHashesConfig {
+    pub hashes: Vec<ethereum_types::H256>,
+}
+
+struct UnprefixedHexH256(pub ethereum_types::H256);
+
+#[derive(Deserialize)]
+struct PreverifiedHashesConfigUnprefixedHex {
+    pub hashes: Vec<UnprefixedHexH256>,
+}
+
+impl PreverifiedHashesConfig {
+    pub fn new(chain_name: &str) -> anyhow::Result<Self> {
+        let config_text = match chain_name {
+            "mainnet" => include_str!("preverified_hashes_mainnet.toml"),
+            "ropsten" => include_str!("preverified_hashes_ropsten.toml"),
+            _ => anyhow::bail!("unsupported chain"),
+        };
+        let config: PreverifiedHashesConfigUnprefixedHex = toml::from_str(config_text)?;
+        Ok(PreverifiedHashesConfig {
+            hashes: config.hashes.iter().map(|hash| hash.0).collect(),
+        })
+    }
+}
+
+impl FromStr for UnprefixedHexH256 {
+    type Err = hex::FromHexError;
+
+    fn from_str(hash_str: &str) -> Result<Self, Self::Err> {
+        let mut hash_bytes = [0u8; 32];
+        hex::decode_to_slice(hash_str, &mut hash_bytes)?;
+        let hash = ethereum_types::H256::from(hash_bytes);
+
+        Ok(UnprefixedHexH256(hash))
+    }
+}
+
+impl<'de> Deserialize<'de> for UnprefixedHexH256 {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: de::Deserializer<'de>,
+    {
+        let hash_str = String::deserialize(deserializer)?;
+        FromStr::from_str(&hash_str).map_err(de::Error::custom)
+    }
+}